A survey of the distribution of the PTS in mycoplasmas will include as wide a range of species as possible. Organisms with PTS activity will be tested for cross reactivity with extracts from mutants of E. coli and S. aureus blocked in EI, HPr or a specific EII in E. coli and with membrane and soluble components (or the purified components as they are identified) of Mycoplasm sp. Kid which will serve as the Mycoplasma reference strains. The Kid strain, will be used to isolate and purify the PTS components of both the soluble and membrane fractions. The isolation of the membrane components will include partial or complete solubilization by detergents, organic solvents (plus or minus urea), salts and enzymes in various combinations. The effects of each of these procedures will be monitored by SDS gel electrophoresis. The apparent correlation between a high affinity for glucose as a fermentation substrate and the presence of a PTS and a low affinity in its absence will be tested by measuring the parameters of sugar uptake in PTS positive species (fermentative Mycoplasma species) and in PTS negative species (fermentative Acholeplasma species).